What If All This Is Not Enough?

Pondering Whether $300 Million and 16.5 Feet of Protection Will Matter

85 Broad Street parking garage after Sandy

At the October 29 meeting of the Battery Park City Authority (BPCA) board, Catherine McVay Hughes raised a potentially troubling question. As BPCA management reviewed plans to spend some $300 million on resiliency measures designed to protect the community against future sea-level rise, extreme-weather events, and climate change, she questioned one of the key assumptions upon which these plans are predicated.

“I think a lot of folks are looking at the depth-to-design elevation flood line,” Ms. McVay Hughes began. “And there was a report that was recently issued… [in which] this technical expert suggested that the 16.5 feet needs to be raised another two to three feet. So I just wanted to make sure that what the Battery Park City will be planning to do will be adequate, as well.”

The metric to which Ms. McVay Hughes was referring comes from the lower end of the mid-range of predicted coastal flood heights for Lower Manhattan by the 2080s. A 2014 report by the New York State Energy Research and Development Authority, entitled “Climate Change in New York State,” noted that middle range for such predictions at the Battery was 16.5 to 18.3 feet. (The lowest bracket was 16.1 feet or less, while the most extreme scenarios ranged up to 19.9 feet.)

Gwen Dawson, the BPCA’s vice president for real property, replied, “we’ve set our design flood elevation not at a specific height but to address a 100 year storm in the year 2050.” This was a reference to a separate framework, contained in the same 2014 report. In that set of projections, the middle range of flood heights at the Battery for the 2050s is estimated at 15.9 to 18.8 feet.

(In these scenarios, the most optimistic outlook is 15.7 feet or below, while the grimmest is 17.5 feet.)

“That’s the design criteria that we’ve established,” Ms. Dawson continued. “That being said, that means that the actual design flood elevation — depending on coastal modeling, depending on where you’re talking about the intervention occurring — may be higher than the 16.5 feet. And in some cases in the South, we already know it’s higher around Pier A and Wagner Park.”

“But certainly, being also aware and cognizant that we’re making our best guess with the projections that have been provided,” she added, “which may be right and which may not be, we want to make sure that whatever it is that we’re doing is flexible and can accommodate adjustments. So that if we determine that we need it to be higher at some point, there is the capability of adding something onto the interventions that we’re designing right now. And certainly, I think that’s going to be important for all the resiliency projects, because we’ll have to adjust. We’re going to have to adapt and adjust these measures over time. So that’s the way that we’re approaching it.”

Ms. McVay Hughes continued, “people may not remember, but there were ten to 30 foot waves out in the harbor during Super Storm Sandy.”

Ms. Dawson replied, “we are designing the Battery Park City Resiliency Projects to withstand storm surge. The storm surge, rainwater events, or sea level rise – that’s all being taken into account.”

Ms. McVay Hughes’s question touches upon an emerging field of scholarship within the broader discipline of climate science. This new school of analysis finds fault with the predictions of a generation of researchers — for precisely the opposite of the reason made popular by media outlets that give a platform to climate-change skeptics. There is a growing body of evidence to indicate that climate scientists have, for decades, been systematically understating the evidence and soft-pedaling projections about global warming.

This movement first attracted notice in 2006, when an Australian government scientist published an essay, “Are Scientists Underestimating Climate Change?” in the journal Eos, concluding that, “many scientists may have consciously or unconsciously downplayed the more extreme possibilities at the high end of the uncertainty range, in an attempt to appear moderate and ‘responsible.'”

This growing shift in perception gathered additional momentum in 2013, when a team of scientists from Princeton University, the University of California at San Diego, the University of Alberta, and St. John’s University published a landmark study, “Climate Change Prediction: Erring on the Side of Least Drama?” in the peer-reviewed journal, Global Environmental Change. This paper argued that a penchant for understatement, “is consistent with a broad pattern in earth science, in play since the mid-19th century, of eschewing catastrophic accounts of natural phenomena.” They also cited, “a broader pattern in science of skepticism toward dramatic explanations of natural phenomena [arising] from the core scientific values of objectivity, rationality, and dispassion, which lead scientists to be skeptical of any claim that might evoke an emotional response.” In a review of this paper, Scientific American noted said of the United Nations Intergovernmental Panel on Climate Change (IPCC) that, “across two decades and thousands of pages of reports, the world’s most authoritative voice on climate science has consistently understated the rate and intensity of climate change and the danger those impacts represent, say a growing number of studies on the topic.”

A 2018 study, “What Lies Beneath: The Understatement of Existential Climate Risk,” argued that, “the bulk of climate research has tended to underplay these risks, and exhibited a preference for conservative projections and scholarly reticence,” while also averring that, “IPCC reports tend toward reticence and caution… downplaying the more extreme and more damaging outcomes.” The 2018 paper concluded that this tendency, “is now becoming dangerously misleading with the acceleration of climate impacts globally. What were lower-probability, higher-impact events are now becoming more likely.”

And this year, Discerning Experts, a new book (by two of the authors of the 2013 study) has made the case that, “climate change and its impacts are emerging faster than scientists previously thought, are consistent with observations that we and other colleagues have made identifying a pattern in assessments of climate research of underestimation of certain key climate indicators, and therefore underestimation of the threat of climate disruption.”

At a March 12 community meeting hosted by the BPCA, on the subject of resiliency, one longtime Battery Park City resident submitted a written question: “As the river is rising what makes you think [protection against] a 100-year storm is sufficient?”

Heather Morgan, the Sustainability and Risk Management Lead from AECOM (the design firm BPCA has retained for its North and South Battery Park City Resiliency Projects), replied, “you have to find this good balance between how far have you designed for a certain scenario in the future, but what if that future kind of shifts or turns? What if sea level rise goes a lot faster than we thought? You want to be able to actually adapt your structure or your alignment or your project. So right now a 100-year event in 2050 is what we consider to be a measurable, understandable projection of what might happen. And if we decide to lean forward further and design to a larger event, that would be something that would be transparently discussed.”

Ms. Dawson added, “We’ve discussed this actually, whether the 2050 100-year event is actually aggressive enough, given the frequency with which things change and the projections change. We are matching our design flood elevations and our standards to those that the City has implemented in their East Side Coastal Resiliency, and the Lower Manhattan Coastal Resiliency Program, because we want them all to be compatible with each other.”

“However, one of the things that we are going to be mindful of as we continue the design,” she continued, “is are there things that we can take into account? Can we perhaps create a foundation that might be strong enough to support a little bit higher measure if we decide that we need to add something more in the future. So we want to make whatever we do adaptable, so that if things change more rapidly than we’re anticipating, we have a plan that we can then add onto or modify in some way to accommodate that.”